1. Field of the Invention
The present invention relates to an apparatus for unloading bulk materials from hopper-type rail cars and, more particularly, relates to a pneumatic unloading apparatus or device incorporating a dual outlet for the pneumatically-actuated discharging of flowable bulk materials from the bottom of a hopper structure, and in which the bulk material is aspirated from the hopper structure into a pair of parallel conduits through spaced discharge orifices designed to minimize or eliminate any possible damage to the bulk material during the procedure of being conveyed therethrough.
In the transport of flowable bulk material through the intermediary of rail cars which contain compartments with hopper bottoms, and in which the bulk materials are generally loaded into the rail cars from inlet parts at the tops thereof, and discharged through hoppers constructed at the bottoms of the rail cars, the bulk materials are frequently subjected to rough handling during the conveyance thereof out of the hoppers. Generally, the hoppers are connected to pneumatic outlets; in essence, an external vacuum which is applied to the outlets in order to assist in the aspiration of the bulk materials being discharged through the bottom hoppers of the rail cars. Although, in many instances, when such flowable bulk materials are constituted of goods which are not easily damaged as a result of rough handling during discharge through the pneumatic outlets of the railway car hoppers, for instance, flour, sugar, cereals, grains, plastics and numerous other kinds of such bulk commodities; nevertheless, under circumstances such rough handling during discharge may damage the bulk materials to an extent so as to possibly render them substantially unfit for their intended use and thereby considerably lower the value of thusly damaged commodities. Thus, for instance, shelled whole peanuts are frequently shipped in bulk quantities in rail cars of the hopper-type, and at their destinations are discharged through orifices in the bottom hoppers by the intermediary of well-known vacuum-pneumatic outlet devices by the application of a vacuum through tubes connected to conduits at the bottom outlets of the hoppers. Usually, the pneumatic outlet device communicates with the bottom of the hopper by a single discharge orifice, and in which hoses or flexible tubes are connected to a pipe or conduit at the bottom of the hopper, and incorporates rotary valve structure for selectively opening and closing the discharge, causing the shelled peanuts to travel through extensive and frequently extremely sharp bends or circuitous flow paths while being aspirated from the hopper at a high velocity under the action of a vacuum. This frequently causes the shelled whole peanuts to be either split into halves, and possibly even broken into smaller parts or fragments, thereby rendering such shelled peanuts unsuitable for use as generally more expensive cocktail peanuts or for applications in which it is desired to dip whole peanuts into chocolate, candy coverings or the like. The splitting or fracturing of the shelled whole peanuts would then necessitate their utilizations in less expensive products, such as peanut butter, peanut brittle or the like which do not require whole peanuts, thereby greatly diminishing their commercial or sales value and producing considerable financial losses to the owner or shipper of the bulk material. Consequently, although in some cases, the essentially rough handling of the flowable bulk materials during discharge from the hopper rail car which is encountered due to the circuitous path to which such materials or commodities are subjected, there is not of any special criticality with regard to any potential commercial loses because of the inherent resistance to damaging by such bulk materials. However, in instances where the commodities are of a generally fragile or easily damaged nature, such as shelled whole peanuts, in the integrity of the material must be maintained to avoid extensive commercial losses, it is desired that abrupt changes in the flow path of the materials being discharged be avoided wherever possible, and that the bulk materials are conveyed in a generally smooth path from the pneumatic outlet apparatus of the rail car hopper under the presence of a vacuum.
In order to be able to attain an improved and inventive discharge for the flowable bulk materials, particularly in instances when the nature of the materials allows them to be easily damaged, such as shelled whole peanuts where it is incumbent to avoid any splitting or fragmenting of the peanuts during discharge from the hopper, the latter is provided with a dual pneumatic outlet consisting of first and second discharge orifices each extending partly across the transverse width of the rail car, the orifices being axially spaced from each other and offset on opposite sides of a longitudinal centerline of the hopper outlet. The discharge orifices communicate the interior of the hopper which consists of a rail car compartment storing a quantity of the bulk material, with a pair of parallel pipes or conduits extending below the respective hopper discharge orifices, with each conduit being connected to respectively one of the discharges so as to, upon appropriate actuation of control valves in the conduits, permit for controlled discharge of the bulk material either simultaneously or selectively through the discharge orifices from the hopper into the parallel extending conduits therebelow. The conduits may be selectively connected at either end thereof to a vacuum-pneumatic outlet for aspirating the materials therethrough from the hopper, thereby ensuring a smooth discharge of the bulk material from the hopper through the discharge orifices, and in view of the linear construction and parallel arrangement of the conduits, avoiding unnecessary bends in the flow path which would possibly lead to damaging of the fragile bulk material.
2. Discussion of the Prior Art
Although numerous hoppers containing hopper outlets of the type considered herein are currently in use, such as vacuum-pneumatic outlet devices employed for the discharging of dry, flowable bulk materials from hopper-type rail cars or similar vehicles, none of these provide for the advantages of having straight, parallel extending conduits positioned below each of the hopper discharge orifices so as to enable the controlled outflow of the bulk material into the conduits in the straightest possible flow bending to ameliorate or possibly even eliminate any undue stress and damage to fragile bulk commodities being rapidly discharged through the vacuum-pneumatic outlet from the hopper.
Talmey, et al. U.S. Pat. No. 2,695,196 discloses a hopper for the storage and transportation of finely divided materials, in which the hopper includes a bottom discharge of a rail car employed for transporting dry, flowable bulk materials, and wherein the rail car is compartmented such that at least two compartments extend transversely of the length of the rail car, in effect, extend across the width of the rail car. Herein, the hopper outlet at the bottom of a downwardly narrowing hopper structure includes a pair of parallel conduits or pipes connected to discharge orifices in the hopper each communicating with a different compartment so as to be able to either concurrently or individually discharge the bulk material from one or both of the compartments in the rail car. Although the construction thereof employs two parallel pipes, the discharge of the flowable bulk material is received by each conduit from a different compartment; whereas, in contrast with the foregoing, pursuant to the present invention, the parallel extending conduits receive the flowable bulk material from a single compartment of the rail car extending across the entire width thereof through the pair of longitudinally spaced discharge orifices arranged at the hopper outlet to straddle an imaginary longitudinal centerline extending across the full width of the rail car. This will enable the present invention to provide for a smoother discharge of a fragile flowable bulk product, such as shelled whole peanuts, into the straight and parallel extending conduits or pipes, and enable the commodity to be aspirated therefrom by the pneumatic outlet apparatus under a vacuum atmosphere with a minimum change in direction of flow for the material
Hornbrook U.S. Pat. No. 2,629,637 relates to a pneumatic unloader for use with the bottom hopper of a vehicle, such as a rail car or truck, and in which a pair of openings communicate with adjacent compartments in the vehicle to allow for simultaneous or selective individual discharge of a flowable bulk material. Again, as in Talmey, et al., there is no discharge of the material from a single compartment through a plurality of discharge orifices communicating with a pair of straight, adjacently arranged and parallel extending conduits or pipes communicating with a vacuum-pneumatic outlet device for aspirating the flowable bulk material in a controlled and smoothly flowing manner.
Gebhardt U.S. Pat. No. 2,746,809 pertains to an ash removal unit in which a single hopper includes a pair of discharge ports straddling a centerline of the hopper, and allowing for concurrent or selective discharge of the ash through either one or both of the discharge orifices. However, there are no parallel conduits or piping connected to a pneumatic or vacuum outlet analogous to the present invention which would facilitate the removal of the material, particularly such as relatively fragile shelled whole peanuts, in a manner avoiding undue bends in the direction of discharge flow which enables the present inventive hopper outlet design to protect the integrity of the relatively fragile bulk commodity.
Other types of outlets for hoppers for the controlled removal of dry, flowable bulk materials in the nature of powders, pellets, granules or the like can be ascertained from various patent publications such as Mundinger, et al. U.S. Pat. No. 3,675,975; Oliver U.S. Reissue Pat. No. 24,916 and Adler U.S. Pat. No. 3,724,909.